1. Field of the Invention
The present invention relates to systems and methods for a delivering flowable substance capable of changing from liquid to solid for use as implants and surgical sealants. More particularly, the present invention relates to systems and methods for forming a fiber from a plurality of flowable substances, including a bulking agent.
2. Description of Related Art
Implants are used for treating a variety of diseases occurring in parts of the body that are extremely difficult to access and/or require relatively non-intrusive treatment techniques. For example, intracranial aneurysms are extremely difficult to treat because they are often formed in hard to reach cerebral blood vessels. If left untreated, hemodynamic forces of normal pulsatile blood flow can rupture fragile tissue in the area of the aneurysm causing a stroke. Some other examples of diseases that may be treated with implants include tumors in areas such as the liver, uterine fibroids, Gastro-Esophageal Reflex Disorder, urinary incontinence, and abdominal aortic aneurysms.
In one type of implant treatment, metallic coils are implanted in the body of a patient in an attempt to occlude blood flow to an aneurysm or tumor. Metal coil systems, however, suffer from several shortcomings. For example, metal coil systems do not form a sealed embolic implant that is encapsulated by tissue. Forming an unsealed embolic implant may result in clot lysis (i.e., disintegration) and/or other types of re-canalization of the targeted vessel. This procedure is also time consuming because it often requires bi-plane X-rays after the placement of each coil and the procedurist normally needs to determine and select the proper size for the coils prior to implantation. Further, when used in the treatment of aneurysms, coils can compact over time because they only fill approximately 40% of the aneurysm volume.
Polyvinyl alcohol (PVA) sponges have also been used as an implant to treat aneurysms and other diseases. However, like the metallic coils described above, PVA sponges have proved to be procedurally difficult to use and have failed to consistently achieve the desired results.
Other embolic systems include the use of polymers in solution, which begin to solidify or precipitate when contacted with blood or other bodily fluids. Such systems, however, suffer from the problem of the polymer solution migrating into undesired parts of the body because of the time delay necessary to cause formation or precipitation of the solid polymer. Migration in these polymer solution systems is particularly problematic when the solution is injected into xe2x80x9chigh flowxe2x80x9d areas, such as vascular systems. Fibers formed from polymer solution systems also tend to suffer from other problems, such as not embolizing well, being overly brittle, or not being biocompatible.
Attempts have also been made to create an implant with adhesives, such as fibrin glues and sealants. However, these materials are thrombogenic and an embolic implant created is only temporary because of lysis of the implant by the body.
In light of the foregoing, there is a need in the art for an improved system and method for delivering a flowable substance that changes from liquid to solid for use as implants and surgical sealants.
Accordingly, the present invention is directed to systems and methods that substantially obviate one or more of the limitations of the related art. To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention includes a system for delivering a flowable substance capable of changing from liquid to solid for use as implants and surgical sealants. The system includes a first reservoir containing a first flowable substance including an bulking agent and a second reservoir containing a second flowable substance including a reacting agent. The system also includes a cannula including a first lumen in fluid communication with the first flowable substance in the first reservoir, a second lumen in fluid communication with the second flowable substance in the second reservoir, a distal end portion wherein the first and second lumens fluidly communicate with one another to mix the first and second flowable substances and thereby form a flexible continuous fiber, and an opening in the distal end portion allowing passage of the fiber out of the distal end portion of the cannula.
In another aspect, at least one of the two flowable substances further includes an additive. The additive includes at least one of a reinforcing agent for providing structural support to the fiber, an active ingredient for providing a treatment to the body, an imaging agent for imaging the fiber, and a bioadhesive agent for adhering the fiber to at least one of itself and body tissue, and wherein after the first and second flowable substances are mixed, the additive is distributed throughout the fiber.
In yet another aspect, the present invention includes a method of delivering a flowable substance that changes from liquid to solid for use as implants and surgical sealants. The method includes introducing a cannula having a first lumen, a second lumen, and an opening in a distal end portion of the cannula into the body. A first flowable substance including an bulking agent is passed through the first lumen and a second flowable substance including a reacting agent is passed through the second lumen. The method also includes mixing the first and second flowable substances in the cannula to form a flexible elongated fiber and moving the fiber through the opening in the cannula into the body to form at least one of an implant and a surgical seal in the body.
In an aspect of the invention, the bulking agent includes alginate, and the reacting agent includes calcium.
In a further aspect, a cutter is provided on the cannula to sever a portion of the fiber passing through the lumen and opening of the cannula.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.